---

yaml
---
r: 175375
b: refs/heads/master
c: e2f74f3
h: refs/heads/master
i:
  175373: 040fa23
  175371: 2db42bb
  175367: b3e7562
  175359: e3cdc93
v: v3

[refs]

@@ -1,2 +1,2 @@
 ---
-refs/heads/master: cf3289d0e701b2f59123bf653c12722a7e32aedb
+refs/heads/master: e2f74f355e9e2914483db10c05d70e69e0b7ae04

trunk/Documentation/cpu-freq/user-guide.txt

@@ -203,6 +203,17 @@ scaling_cur_freq :		Current frequency of the CPU as determined by
 				the frequency the kernel thinks the CPU runs
 				at.
 
+bios_limit :			If the BIOS tells the OS to limit a CPU to
+				lower frequencies, the user can read out the
+				maximum available frequency from this file.
+				This typically can happen through (often not
+				intended) BIOS settings, restrictions
+				triggered through a service processor or other
+				BIOS/HW based implementations.
+				This does not cover thermal ACPI limitations
+				which can be detected through the generic
+				thermal driver.
+
 If you have selected the "userspace" governor which allows you to
 set the CPU operating frequency to a specific value, you can read out
 the current frequency in

trunk/arch/x86/kernel/cpu/cpufreq/acpi-cpufreq.c

@@ -764,14 +764,15 @@ static struct freq_attr *acpi_cpufreq_attr[] = {
 };
 
 static struct cpufreq_driver acpi_cpufreq_driver = {
-	.verify = acpi_cpufreq_verify,
-	.target = acpi_cpufreq_target,
-	.init = acpi_cpufreq_cpu_init,
-	.exit = acpi_cpufreq_cpu_exit,
-	.resume = acpi_cpufreq_resume,
-	.name = "acpi-cpufreq",
-	.owner = THIS_MODULE,
-	.attr = acpi_cpufreq_attr,
+	.verify		= acpi_cpufreq_verify,
+	.target		= acpi_cpufreq_target,
+	.bios_limit	= acpi_processor_get_bios_limit,
+	.init		= acpi_cpufreq_cpu_init,
+	.exit		= acpi_cpufreq_cpu_exit,
+	.resume		= acpi_cpufreq_resume,
+	.name		= "acpi-cpufreq",
+	.owner		= THIS_MODULE,
+	.attr		= acpi_cpufreq_attr,
 };
 
 static int __init acpi_cpufreq_init(void)

trunk/arch/x86/kernel/cpu/cpufreq/powernow-k7.c

@@ -714,14 +714,17 @@ static struct freq_attr *powernow_table_attr[] = {
 };
 
 static struct cpufreq_driver powernow_driver = {
-	.verify	= powernow_verify,
-	.target	= powernow_target,
-	.get	= powernow_get,
-	.init	= powernow_cpu_init,
-	.exit	= powernow_cpu_exit,
-	.name	= "powernow-k7",
-	.owner	= THIS_MODULE,
-	.attr	= powernow_table_attr,
+	.verify		= powernow_verify,
+	.target		= powernow_target,
+	.get		= powernow_get,
+#ifdef CONFIG_X86_POWERNOW_K7_ACPI
+	.bios_limit	= acpi_processor_get_bios_limit,
+#endif
+	.init		= powernow_cpu_init,
+	.exit		= powernow_cpu_exit,
+	.name		= "powernow-k7",
+	.owner		= THIS_MODULE,
+	.attr		= powernow_table_attr,
 };
 
 static int __init powernow_init(void)

trunk/arch/x86/kernel/cpu/cpufreq/powernow-k8.c

@@ -1398,14 +1398,15 @@ static struct freq_attr *powernow_k8_attr[] = {
 };
 
 static struct cpufreq_driver cpufreq_amd64_driver = {
-	.verify = powernowk8_verify,
-	.target = powernowk8_target,
-	.init = powernowk8_cpu_init,
-	.exit = __devexit_p(powernowk8_cpu_exit),
-	.get = powernowk8_get,
-	.name = "powernow-k8",
-	.owner = THIS_MODULE,
-	.attr = powernow_k8_attr,
+	.verify		= powernowk8_verify,
+	.target		= powernowk8_target,
+	.bios_limit	= acpi_processor_get_bios_limit,
+	.init		= powernowk8_cpu_init,
+	.exit		= __devexit_p(powernowk8_cpu_exit),
+	.get		= powernowk8_get,
+	.name		= "powernow-k8",
+	.owner		= THIS_MODULE,
+	.attr		= powernow_k8_attr,
 };
 
 /* driver entry point for init */

trunk/drivers/acpi/processor_perflib.c

@@ -167,6 +167,19 @@ int acpi_processor_ppc_has_changed(struct acpi_processor *pr)
 		return cpufreq_update_policy(pr->id);
 }
 
+int acpi_processor_get_bios_limit(int cpu, unsigned int *limit)
+{
+	struct acpi_processor *pr;
+
+	pr = per_cpu(processors, cpu);
+	if (!pr || !pr->performance || !pr->performance->state_count)
+		return -ENODEV;
+	*limit = pr->performance->states[pr->performance_platform_limit].
+		core_frequency * 1000;
+	return 0;
+}
+EXPORT_SYMBOL(acpi_processor_get_bios_limit);
+
 void acpi_processor_ppc_init(void)
 {
 	if (!cpufreq_register_notifier

trunk/drivers/cpufreq/cpufreq.c

@@ -647,6 +647,21 @@ static ssize_t show_scaling_setspeed(struct cpufreq_policy *policy, char *buf)
 	return policy->governor->show_setspeed(policy, buf);
 }
 
+/**
+ * show_scaling_driver - show the current cpufreq HW/BIOS limitation
+ */
+static ssize_t show_bios_limit(struct cpufreq_policy *policy, char *buf)
+{
+	unsigned int limit;
+	int ret;
+	if (cpufreq_driver->bios_limit) {
+		ret = cpufreq_driver->bios_limit(policy->cpu, &limit);
+		if (!ret)
+			return sprintf(buf, "%u\n", limit);
+	}
+	return sprintf(buf, "%u\n", policy->cpuinfo.max_freq);
+}
+
 #define define_one_ro(_name) \
 static struct freq_attr _name = \
 __ATTR(_name, 0444, show_##_name, NULL)
@@ -666,6 +681,7 @@ define_one_ro(cpuinfo_transition_latency);
 define_one_ro(scaling_available_governors);
 define_one_ro(scaling_driver);
 define_one_ro(scaling_cur_freq);
+define_one_ro(bios_limit);
 define_one_ro(related_cpus);
 define_one_ro(affected_cpus);
 define_one_rw(scaling_min_freq);
@@ -905,6 +921,11 @@ static int cpufreq_add_dev_interface(unsigned int cpu,
 		if (ret)
 			goto err_out_kobj_put;
 	}
+	if (cpufreq_driver->bios_limit) {
+		ret = sysfs_create_file(&policy->kobj, &bios_limit.attr);
+		if (ret)
+			goto err_out_kobj_put;
+	}
 
 	spin_lock_irqsave(&cpufreq_driver_lock, flags);
 	for_each_cpu(j, policy->cpus) {

trunk/include/acpi/processor.h

@@ -295,6 +295,7 @@ static inline void acpi_processor_ffh_cstate_enter(struct acpi_processor_cx
 void acpi_processor_ppc_init(void);
 void acpi_processor_ppc_exit(void);
 int acpi_processor_ppc_has_changed(struct acpi_processor *pr);
+extern int acpi_processor_get_bios_limit(int cpu, unsigned int *limit);
 #else
 static inline void acpi_processor_ppc_init(void)
 {
@@ -316,6 +317,11 @@ static inline int acpi_processor_ppc_has_changed(struct acpi_processor *pr)
 	}
 	return 0;
 }
+static inline int acpi_processor_get_bios_limit(int cpu, unsigned int *limit)
+{
+	return -ENODEV;
+}
+
 #endif				/* CONFIG_CPU_FREQ */
 
 /* in processor_throttling.c */

trunk/include/linux/cpufreq.h

@@ -232,6 +232,7 @@ struct cpufreq_driver {
 	/* optional */
 	unsigned int (*getavg)	(struct cpufreq_policy *policy,
 				 unsigned int cpu);
+	int	(*bios_limit)	(int cpu, unsigned int *limit);
 
 	int	(*exit)		(struct cpufreq_policy *policy);
 	int	(*suspend)	(struct cpufreq_policy *policy, pm_message_t pmsg);